Edible oils having hypocholesterolemic properties

ABSTRACT

Edible cooking and salad oil compositions having enhanced hypocholesterolemic properties comprising from about 2.0 to about 6.9 wt. % of a plant sterol; a solubilizing agent therefor such as free fatty acids, fatty acid esters, and alkanols; and a clear, liquid glyceride base oil.

United States Patent Jandacek EDIBLE OILS HAVING HYPOCHOLESTEROLEMICPROPERTIES Feb. 11, 1975 3,751,569 8/1973 Erickson 424/173 Primary-Examiner-Shep K. Rose Attorney, Agent, or F irm-John B. Goodman;Richard C. Witte; Jack D. Schaeffer [57] ABSTRACT Edible cooking andsalad oi] compositions having enhanced hypocholesterolemic propertiescomprising from about 2.0 to about 6.9 wt. of a plant sterol; asolubilizing agent therefor such as free fatty acids, fatty acid esters,and alkanols; and a clear, liquid glyceride base oil.

7 Claims, N0 Drawings- EDIBLE OILS HAVING HYPOCHOLESTEROLEMIC PROPERTIESBACKGROUND OF INVENTION This invention relates to edible oils andfoodstuffs comprising such oils. Said oils having dissolved therein asufficient amount of a plant sterol to give significanthypocholesterolemic activity. As used herein, the termhypocholesterolemic means reducing the cholesterol level in the blood ofwarm-blooded animals or inhibiting or reducing the build up ofcholesterol in the blood. The term plant sterol includes all non-animalsterols, that is, not only phytosterols (plant sterols characteristic ofhigher plants) but also mycosterols (plant sterols from lower plants).For a more complete description of plant sterols, see Deuel, Jr., HarryJ., The Lipids, Volume l, Interscience Publishers (New York 1951) atpages 321 and 348. These compositions remain clear at normal homerefrigerator temperatures. Moreover, the added plant sterols showresistance to precipitation from the oil in the presence of water, forexample, when a vinegar and oil emulsion is prepared. Thus, the plantsterols are added to the oils in effective amounts without affecting theappearance of the oils.

The addition of hypocholesterolemic additives, including plant sterolsand plant sterol esters, to oil is old. [See Wruble, et al., U.S. Pat.No. 3,085,939; Jones, U.S. Pat. No. 3,203,862; Beveridge, Canadian Pat.No. 567,202; and Peterson, et al., 50 Journal of Nutrition 191-210(1953)]. Belgium Pat. No. 753,648 (Jan. 18, 1971) which corresponds toco-pending U.S. Pat. application Ser. No. 217,708 to B. A. Ericksonfiled July 17, 1969 now U.S. Pat. No. 3,751,569 dated Aug. 7, 1973relates to clear cooking and salad oils having hypocholesterolemicproperties. The Belgium patent teaches the enhanced solubility of plantsterol esters over the free sterol in edible oils. The above-mentionedpatent to Wruble, et al., relates to a pharmaceutical compositioncomprising a water-oil emulsion which contains plant sterols and certainemulsifing agents among which are free fatty acids.

The problem which has beset the prior art, which is representativelydepicted by the above-mentioned patents and publications, is that plantsterols characteristically have very limited solubility in any solventsystem much less edible oils. But in order for edible oil compositionsto exhibit hypocholesterolemic properties to a useful extent, it isnecessary that the hypocholesterolemic agent (herein plant sterols) bepresent in true solution in the edible oil base at a level of from about2.0 to about 6.0 wt. Further, it is required that oils containing plantsterols remain clear at normal home refrigerated temperatures, i.e.,that the added sterol not percipitate from the oil at reducedtemperatures. Also, it is required that the added sterol resistprecipitation from the oil on the addition of water.

Accordingly, it is an object of this invention to provide edible oilcompositions, such as, salad and cooking oils and foodstuffs comprisingsuch oils, which remain clear at reduced temperatures and which exhibitenhan'ced hypocholesterolemic activity occasioned by the presence insaid oils of plant sterols, at concentration levels which heretoforehave not been practicable.

SUMMARY OF THE INVENTION Briefly stated, the edible oil compositions ofthis invention comrpise a clear liquid glyceride base oil containing asan active hypocholesterolemic agent from about 2.0 to about 6.0 wt. of aplant sterol, and from about 0.5 to about 15.0 weight ofa solubilizingagent for said plant sterol selected from the group consisting of fattyacids having from six to 18 carbon atoms, monoesters of said fatty acidswith polyhydric alcohols and alkanols having from about six to about 18carbon atoms.

DETAILED DESCRIPTION. OF INVENTION It is accepted in the art that anelevated cholesterol concentration in the circulating body plasmasindicates a set of metabolic abnormalities which frequently manifest anatherosclerotic condition. It is also accepted that exogenouscholesterol introduced from the gut to the circulating plasmas advances,possibly causes, atherosclerotic disease. Consequently, the art hassuggested numerous therapeutic means to prevent the ab sorption ofcholesterol from the gut. Conspicuously successful among these means isthe utilization of plant sterols in dietary compositions. However, thereis no unanimous agreement in the art which explains the efficacy ofplant sterols in reducing the absorption ofcholesterol from the gut.This lack of unanimity probably indicates that plant sterols function bymore than one mechanism in the overall suppression of cholesterolabsorption.

The present invention originates from focusing attention on a particularmechanism, and makes available a collection of dietary compositionswhich enhance this particular mechanism in the suppression ofcholesterol absorption. These oil-based dietary compositions comprise aninherently non-absorbable steroid, for example, certain food grade plantsterols and a solubilizing agent for such steroids. I

The mechanism which is central to this invention may be appreciated fromthe following comments: It is known that oil is essential for theabsorption of cholesterol. Further, it is known that cholesterol istrans ported from an oil-solubilized form in the intestine to themucosal cells for absorption into the lymph. The steps leading toultimate absorption may generally be stated as follows: A cholesterolbearing oil phase is progressively dispersed as minute oil droplets inthe predominately aqueous food mixture during passage from the stomachto the small intestine. Thereafter, emulsifing agent such as bile acidsfatty acids, and monoglycerides thereof progressively attack thediscrete oil droplets to form colloidal micelles which are presented tothe mucosal cells for absorption of their lipid components. Fats andoils, however, are preferentially taken from the discrete oil dropletsby the emulsifing agents.

The result is that the steriod components of the oil droplets undergo arelative enhancement in concentration as micelle formation proceeds.Since steroids are so difficultly soluble, a condition of saturation issoon reached whereupon crystallization of the steroids commences. It hasbeen established that crystalized steroids cannot again be effectivelysolubilized for absorption. Consequently, the crystalized steroids areexcreted.

inherently nonabsorbable steroids such as certain plant sterols andtheir carboxylic acid esters effectively promote the crystallization ofcholesterol from the oil droplets by competing with cholesterol foroccupancy in the oil droplet. The overall result is that a state ofsaturation with respect to cholesterol is reached thereby initiating itscrystalliztion.

A problem which has beset the art is that the inherently nonabsorbablesteroids are, as is cholesterol, exceeding difficult to solubilize indietary compositions such as salad and cooking oils. Consequently, theart tion or rearrangement of animal or vegetable fatty materials,followed by removal of the higher melting solids formed during thereaction. For an example of this procedure, see US. Pat. No. 2,442,532.Another group of has not been able to fully exploit the above mechanism5 oils suitable for use as the liquid glyceride base oil is insuppressing the absorption of cholesterol. The presthat group of oils inwhich one or more short-chain ent invention solves this problem byincorporating into fatty acids, such as acetic acid, and propanoic acid,redietary compositions certain steroid solubilizing agents place inpart, the long chain fatty acids present in natusuch that greaterconcentrations of inherently nonabral triglyceride oils. sorbablesteroids may be incorporated into such dietary Other useful clear liquidglyceride oils can be derived compositions. from animal, vegetable andmarine sources, including The principal dietary compositions encompassedby mixtures of various of such oils. Particularly preferred thisinvention are cooking and salad oils. Additionally, oils for use in thisinvention are triolein cottonseed oil, the development fullycontemplates oleaginous gel soybean oil, and mixtures thereof.foodstuffs such as peanut butter, mayonnaise, ice l5 cream, andmargarine spreads which incorporate such THE INHERENTLY NONABSORBABLESTEROIDS il As stated above, all nontoxic steroids capable of de- Theinherently nonabsorbable steroids are not necescreasing the solubilityof cholesterol in a colligative sarily restricted to the conventionalplant sterols but manner within the gut are encompassed by thisinvenencompass all nontoxic steroids and like compounds tion. Morespecifically, plant sterols are encompassed which compete withcholesterol for occupancy in the by this invention. For example,suitable free plant steoil droplets, thereby promoting crystallizationof inrols for practice for this invention are 0zsitosterol, B-sigestedcholesterol so that it may be excreted without tosterol, stigmasterol,ergosterol, and campesterol. absorption. Suitable solubilizing agentsfor the inher- Typically the solubility of the above-mentioned freeently nonabsorbable steriods may be selected from plant sterols in theabovementioned glyceride base oils nontoxic compounds such as alcohols,free fatty acids, is in the range from about 0.5 to 1.5 wt. These conandsimple esters of such fatty acids such as monoglyccentration levels areconsidered too low to provide a erides. noticeable hypocholesterolemiceffect. However, as

The components of the edible compositions of this will become apparentbelow, by means of the copresinvention, namely: the oil base, theinherently nonabence of a suitable steroid solubilizing agent, theconsorbable steroid, and the solubilizing agent are decentration rangeof the above-mentioned free plant stescribed in greater detail below.Also described are recrol can be raised to from about 1.5 to about 6.0wt. ommended procedures for combining the above men- The preferred rangefor purposes of practicing this intioned components to yield the foodcompositions of vention is from about 2.0 to about 6.0 wt. of such thisinvention. And lastly there is presented a series of free plant sterolsin the above-described glyceride base examples featuring thehypocholesterolemic edible oils il of this invention.

THE STEROID SOLUBILIZING AGENT THE OIL BASE The steroid solubilizingagents encompassed by this A wide variety of clear, liquid glyceridebase oi can invention are free fatty acid, alkanols, and esterified beused in the compositions Of this invention. Pure tl'ifatty acids such asmgnoglycerides, Among the most glycerides liquid at normal homerefrigerator temperapreferred saturated and unsaturated fatty acidsaretures, such as triolein, are suitable. Also included those havingfrom 6 to 18 carbon atoms. For a more among suitable oils are the socalled natural salad oils l te description of these fatty acids, seeMarkley, such as for example li il, ufl Seed Klare 8., Fatty Acids, PartI, lnterscience Publishers, flower oil, and sesame seed oil. Othernaturally occur- I (N Y k 1960) Saturated fatty id i ring liquidglyceride oils such as cottonseed oil and i more h about 18 carbon atomshav a t d 60m Oil are also Useful; these Oils are g n a P l m tocrystallize from an oil solution and hence are not nary winterization,dewaxing, or similar treatment to i bl f practice f h present inventionremove the higher melting Stearlnes before being used Examples ofsuitable fatty acids are oleic, steric, palas an oil base. Certain otheroils such as soybean oil can i i d l -k; be Partially hydrogenatedbefore use to improve their Examples of suitable fatty acid esters aresorbityl deresistance to oxidative deterioration during prolongedrivatives d l id h as monoolein, monolaustorage periods; the highermelting solids formed durrin, monostearin, and monopalmitin. ing thehydrogenation treatment are preferably re- Table 1 illustrates theenhanced solubility of certain moved by winterization. plant sterols inliquid glyceride base oils occasioned by Suitable clear liquid glyceridebase oils can also be the presence of certain steroid solubilizingagents enobtained by directed, low temperature interesterificacompassedby this invention.

TABLE I Steroid Solubility Steroid Component Oil Base Solubilizing AgentWt. Wt. at 25C.

B-Sitosterol Triolein Oleic Acid Y 5.0 3.5 B-Sitosterol Triolein OleicAcid 10.0 3.8 fl-Sitosterol Triolein Hexanoic Acid 5.0 4.0 ,B-SitosterolSoybean Oil Hexanoic Acid 10.0 5.0 Stigmasterol Soybean Oil Lauric Acid5.0 3.5

I-IYPOCI-IOLESTEROLEMIC EDIBLE OILS,

PREPARATION 1 by evaporation.

In general, the concentration level. of the steroid should be within therange of from about 2.0 to about 6.0 wt. and the correspondingconcentration of the steroid solubilizing agent should preferably bewithin the range of from about 0.5 to about 15.0 wt. The edible oilcompositions herein described reduce the level of cholesterol in theblood that is directly of dietary origin up to 65% compared when nohypocholesterolemic additives are utilized. The hypocholesterolemicedible oils can be utilized as such for purposes of cookingand salad"dressings, or can be incorporated with other food ingredients to yieldfood products as diverse as mayonnaise and bread, and when utilized asan ingredient in other foods, the hypocholesterolemic activity isretaine d. A

The following examples further illustrate the novel edible oilcompositions of this invention.

W EXAMPLEI Cle'ar cooking and salad oil compositions were pre-- pared bydissolving a'free plant sterol in a liquid triglyceride edible oil.Table II gives these compositionsand shows the identity of thetriglyceride, the concentration and identity of the plant sterol, andthe identityand TABLE 11 Concentration Identity and and IdentityConcentration Identity of -of Plant of Sterol Triglyceride Sterolsolubilizing Agent Soybean Oil B-Sitosterol 5.0% Oleic Acid 2.5% CornOil B-Sitosterol 5.0% Lauric Acid 2.5% I I Substantially equivalentresults are obtained as in Example I when the B-sitosterol is replacedby. an equivalent amount of a-sitosterol, stigmasterol, egosteroLandcampesterol, respectively.

Substantially equivalent results are obtained as in Example l when thesteroid solubilizing agent is palmit'ic acid, stearic acid, monoolein,hexanol, monolaurin, monostearin, and monopalmitin, respecitvely.

What. is claimed is: I

1. A food composition having hypocholesterolemic activity comprisingatleast one edible oilin homogeneous admixture with (a)'-from vabout2.0,to about 6.0 wt. of a plant sterol; (b) fromabout 0.5 to about 15.0wt.

% of a solubilizing compound selected from the group I consisting ofsaturated and unsaturated fatty acids having from six to 18 carbonatoms, monoesters of said fatty acids with polyhydric alcohols, andalkanols hav'-- ing from six to 18 carbon atoms.

2. Theproduct of claim 1 whereinthe food composition is a clear cookingand salad oil composition.

3. The cooking and salad'oil composition of claim 2 wherein the plantsterol is a-sitosterol, B-sitosteroL- 'campesterol; or mixturesstigmasterol, egosterol, thereof. v

4. The cooking and salad oil composition of claim 3 wherein the base oilisselected from'the group consisting oftriolein, soybean oil, cottonseedoil, and mixtures thereof. 3

5. The food composition of claim 1 wherein the solubilizing compound isselected from the group consisting of saturated and unsaturated fattyacids having from 6 to 18 carbon atoms.

6. The food composition of claim 1 wherein the solu-' bilizing compoundis selected from the group consisting of monoesters of saturated andunsaturated fatty acids having from 6 to 18 carbon atoms.

7. The food composition of claim 1 wherein the solubilizing compound isselected from the groupconsisting of alkanols having from six to 18carbon atoms.

1. A FOOD COMPOSITION HAVING HYPOCHOLESTEROLEMIC ACTIVITY COMPRISING ATLEAST ONE EDIBLE OIL IN HOMOGENEOUS ADMIXTURE WITH (A) FROM ABOUT 2.0 TOABOUT 6.0 WT. % OF A PLANT STEROL; (B) FROM ABOUT 0.5 TO ABOUT 15.0 WT.% OF A SOLUBILIZING COMPOUND SELECTED FROM THE GROUP CONSISTING OFSATURATED AND UNSATURATED FATTY ACIDS HAVING FROM SIX TO 18 CARBONATOMS, MONOESTERS OF SAID FATTY ACIDS WITH POLYBYDRIC ALCOHOLS, ANDALKANOLTS HAVING FROM SIX TO 18 CARBON ATOMS.
 2. The product of claim 1wherein the food composition is a clear cooking and salad oilcomposition.
 3. The cooking and salad oil composition of claim 2 whereinthe plant sterol is Alpha -sitosterol, Beta -sitosterol, stigmasterol,egosterol, campesterol, or mixtures thereof.
 4. The cooking and saladoil composition of claim 3 wherein the base oil is selected from thegroup consisting of triolein, soybean oil, cottonseed oil, and mixturesthereof.
 5. The food composition of claim 1 wherein the solubilizingcompound is selected from the group consisting of saturated andunsaturated fatty acids having from 6 to 18 carbon atoms.
 6. The foodcomposition of claim 1 wherein the solubilizing compound is selectedfrom the group consisting of monoesters of saturated and unsaturatedfatty acids having from 6 to 18 carbon atoms.
 7. The food composition ofclaim 1 wherein the solubilizing compound is selected from the groupconsisting of alkanols having from six to 18 carbon atoms.